A conventional abrasive sheet is generally prepared by coating a first adhesive (a make-coat adhesive) on one side of a substrate such as a cloth, paper, and film; electrostatic-coating an abrasive material thereon, followed by pre-curing; coating a second adhesive (a size-coat adhesive) thereon, followed by pre-curing; winding the resulting laminate; and subjecting the jumbo roll-type product to final curing. A cross-sectional view of a conventional abrasive sheet thus prepared is shown in FIG. 1.
However, the use in such a process of an abrasive material having a particle size of #2000 or less (10 μm or less) is difficult due to its inconsistent behavior during the electrostatic- or gravity-coating, especially under a high humid condition.
In addition, an abrasive sheet comprising a micro-sized and fine abrasive material tends to generate frequent scratches on the work piece during a polishing operation and also forms a water membrane thereon when applied to wet polishing, which causes insufficient polishing. Therefore, an embossed abrasive sheet is preferred: An embossed-type abrasive sheet comprising a micro-sized abrasive material does not suffer from the above-mentioned problems due to the presence of grooves. Generally, the embossing of a particular dimension enhances the grinding speed and surface roughness (Ra and Rmax values) of the work piece, and therefore, it is important to control the size and shape of the embossing pattern.